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Topic: Is Continous Autofocus a big deal for those who shoot video (Read 30765 times)

You're right, Leadfingers. Live events are definitely one instance when auto focus (if it works well) can be handy. Especially when it's a single camera shoot and you can't zoom in to get your focus first.

For those of you who shoot a lot of video, how do you maintain focus during a live event? I mean, with the little 3" screen on the T3i that I use, it's pretty much impossible to truly see what's clearly in focus.

I don't always need it, but I frequently would love to have it. Given two identical SLRs with and without the ability, I'd take the ability. I'd probalby pay up to 20% or $200 to have it in a midprice (<$1000) SLR and up to $300 on a higher price SLR.

Yes, it's a VERY big deal. For those of us who aren't Steven Spielberg, but still shoot a lot of video, it's a big deal.

Half of the problem with this conversation is that the Manual Focus guys almost sound like you're being being physically forced to use it. If you don't want it... THEN DON'T.

For those of you who shoot a lot of video, how do you maintain focus during a live event? I mean, with the little 3" screen on the T3i that I use, it's pretty much impossible to truly see what's clearly in focus.

Spielberg uses MF as does the rest of the industry. I shoot pretty much nothing but live music, over 70 bands in the last 7 months. I focus with a follow focus and either a 5" Marshall monitor or my Zacuto EVF. The EVF has peaking which artificially sharpens the image, making it much easier to pull focus. And in those situations I'm usually using the 35L or 50L at f/2, so it's not like I have tons of DOF to work with. I would never try to pull focus off the back of the screen, and don't know any professionals that do either.

The thing is, if these things did have AF people would be complaining that it was focusing on the wrong thing or at the wrong time. I'm sure we'll have it one day, but until then I'll be fine with manual focus. The film industry has been using MF for as long as it's been around, and they continue to do so. I think this sudden demand for autofocus on video DSLRs stems from photographers being used to having AF for stills.

Maybe if every video camera had a single, fixed lens that it may be easier, but when you throw tons and tons of lenses into the mix it probably makes it much more difficult to create a reliable AF system. Most of the consumer video cameras in recent years have tiny sensors and TONS of DOF, which probably makes it much easier for them to have AF. If you want AF you should try one of those.

« Last Edit: March 12, 2012, 04:23:28 PM by Axilrod »

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5DIII/5DII/Bunch of L's and ZE's, currently rearranging.

SPG

For cinema? No need for it. For live events? Well...not really unless it's really good AF, and even then most pros would continue to use their EVFs, extra monitors, and Z-finders. Would it be nice to have occasionally? Sure, but it's not the most important part of the feature list. Are there times where it would be really useful? Last week I was shooting a live event in pouring rain so I couldn't use a monitor, and then my viewfinder fogged up. A push to focus function would have been a life saver there, but that's a pretty uncommon situation. Even in that situation an AF that was either always on or always off wouldn't have been ideal. A push to focus option with an easily accessible button could have worked, or the ability to zoom the screen while shooting would've done the trick too.

I wouldn't say I do a lot of video, but it something that I'm doing more and more. I use an Olympus EPL-1 for my videos. It has continuous AF and I use this occasionally and I enjoy using it. If it wasn't for the noisy lens autofocus sound, I'd probably use it more. However, I'm tending to use wide aperture manual focus lenses with an adapter, and obviously the camera won't AF with these. Therefore, I'll say that continuous autofocus isn't needed. But it is handy to have. I wasn't really aware that Canon's latest cameras lacked this and I'm a little surprised. It would seem like an easy thing to implement.

One thing my camera lacks that later models picked up was the use of face detection AF in video mode. I can appreciate that professionals would never use such a thing, but for casual / fun / family videos, this would be a great feature to have.

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Camera Obscura

gene_can_sing

I shot mostly video. Although for studio stuff, continuous autofocus is not important, but I can see how it would be great for certain things. For example, if you wanted to shoot a steadycam shot with a longer lens to get a shallow DOF. It would be almost impossible to keep in focus without Autofocus.

That would be a great use for it.

I'm thinking the 4K VDSLR will probably have it, especially since rumors have it that it might be mirrorless. The mirror is completely useless for video, so not sure why they would have it in that camera.

Just wondering for those of you who shoot a lot of video; Is continuous auto focus (D800 has it, 5DmkIII does not) a good feature?

It's not enough for the body to have continuous AF. It's the body/lens combo.

What I found when I was looking into this is that DSLRs don't autofocus very well in video mode. Maybe the D800 is better, but I saw youtube videos of the Nikon APS-C cameras and their continuous autofocus behaved in a manner pretty similar to how the 5D Mark II would if you were to pound on the "autofocus" button in video mode.

That is, when it focus, the lens lurches and hunts, it doesn't glide smoothly like a camcorder or for that matter, a manual focus pull.

I have a Panasonic GF2 which seems to autofocus much more smoothly in video mode than any SLR. If video is important to you, and AF in video is also important I'd suggest taking a serious look at either a panasonic GH2 or a camcorder.

SLRs are fine for video, but the AF in video mode isn't really usable (at least none of the ones I've seen are) -- you need to be willing to manually focus.

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darinf

For me, I would love to have autofocus. I shoot with my 5D2 and 7D on a Steadicam. And since I don't have a Spielberg budget, I don't have wireless remote monitoring and a focus puller on my staff, autofocus on a Steadicam would be great.

Sure it wouldn't be perfect, but it would give me a fighting chance in low light situations where I can't stop down the lens.

For me, I would love to have autofocus. I shoot with my 5D2 and 7D on a Steadicam. And since I don't have a Spielberg budget, I don't have wireless remote monitoring and a focus puller on my staff, autofocus on a Steadicam would be great.

Sure it wouldn't be perfect, but it would give me a fighting chance in low light situations where I can't stop down the lens.

The 5D Mark II will autofocus in video ("AF on" button next to the left of the AE lock). The main problem is not that it doesn't autofocus continuously as much as it is that the autofocus is unusable for video because it jerks around instead of moving slowly.

As far as I can tell from the youtube video of the Nikon cameras like the D7000 and D5100, the autofocus is every bit as violent as it is on the Canon, except that you yield control over when it kicks in.

felix arnold

Not to establish Continuous Autofocus in the 5D mk III is a purely marketing driven decision. It does not show any respect of the customer who invested in a canon dslr system.I'm a happy user of the 5D mk II, but I feel abused as a money spending ape by these people of the marketing department. Any customer will notify the one and only intention of that decision. That was a "Bad, Bad Idea" of canon. The company made lots of money with customers going for a product, which was a logic combination of what historically belongs together. - Movies are still Pictures with Frame Rates off 24+. -Even the analog movie material was the same as the one used for stills. Canon should have not decided for fooling their customers in such a blunt way.

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jrod

I have shot only video for many years and I am not saying it is right or wrong but almost any professional video camera system with interchangeable lenses does not have an auto focus system of any kind. I have used them to shoot sports, weddings, commercials, etc with no focus problems. The difference is they have a much higher resolution viewfinders that assist in getting an accurate focus. But for the moment lets talk of the professional cameras that do include an auto focus, they have some trade offs. For one they typically have very small sensors so the DOF is never very shallow so if it misses focus it is much less noticeable. Also the focusing mechanism is not extremely fast (compared to an SLR), so things in the shot roll in and out of focus instead of violently snapping around, this is much more pleasant to the eye. The lenses are also designed for video, they are extremely quiet.

Secondly lets look at the physical hardware requirements for a true auto-focus system on a HDSLR, many of which would cause compromises to the still picture quality and functionality. Look at Sony's system that requires a semi-transparent mirror that results in a loss of light to the sensor and requires a digital viewfinder. The other issue as I mentioned above is still picture lenses are not designed for video, they are extremely noisy which is a nightmare in post, not to mention the focus mechanism and algorithms are designed to achieve focus as quickly as possible, and it is not very pleasing to the eye.

Now I am not against auto-focus, there are times it could be helpful (boom or steadycam shots), but even then from my experience they cause more missed shots than good ones. Everything requires some trade offs, I think a lot more people would be upset if the still picture quality/functionality/speed was compromised to please the people that want/need a full time auto focus system. At the end of the day it is a still camera with video functions.

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felix arnold

“At the end of the day it is a still camera with video functions” - Think twice before promoting it like that. Might just be that kind of shortsighted propaganda, which pisses customers off. Nikon did it, Panasonic did it, … “Everything requires some tradeoffs.” For sure that ignorant kind of wise guy talking; - claiming it would not be possible without infringing with the photo-functions,- will cause some major tradeoffs. Are you claiming, that while performing 6 frames per second on a fast moving object your camera does not keep the object in focus? Are you claiming that the canon video cameras do not catch up the focus on moving objects? Your next consumer DSLR will anyway be obliged to carry an Autofocus system for video. How will you promote that? “Not for professionals” Arrogance does not sell!

I dunno, I've been in the film and video industry for decades and maybe my "pro" thinking is old fashioned, but I just can't imagine how autofocus could possibly work on a large sensor video camera. There's a reason that no large sensor cameras have them - they just don't work and never really could, unless you're stopped way down. Most video cameras have tiny sensors so no DOF, so they have autofocus and it's fine. Still cameras are looking at a single image. I'm a steadicam operator and I cannot imagine, dream as it might be, shooting with super35 or larger and having a non-human focus puller understand what's happening in the frame at anything greater than f8 or so. Maybe I'm just stupid and not-forward thinking, but I'm just perplexed by the people saying this feature will need to be included in future large sensor cameras - it sounds like a lot of still photographers that dabble in video - to my way of thinking it's like saying all still cameras in the future should include a feature that automatically frames the photo correctly - how could the camera possibly know what's correct?

The video above demonstrates my point perfectly - that autofocus is completely unusable for any application except maybe some sort of personal use - a kids party or something, but otherwise I'd be horrified to turn in footage that had a focus pull like that to any client. It'd probably mark the end of a career, I'd certainly fire any camera person I hired that focused like that, manual or auto.